volfs

- Volume Management file system

Description

Note - The Volume Management file system might not be included in future Solaris
releases.

volfs is the Volume Management file system rooted at root_dir. The default
location for root-dir is /vol, but this can be overridden using the
-d option of vold (see vold(1M)). This file system is maintained by
the Volume Management daemon, vold, and will be considered to be /vol
for this description. Refer to vold(1M) for details on how to use the
volfssmf(5) service.

Media and removable media devices (without media) can be accessed in a
logical manner (no association with a particular piece of hardware), or a
physical manner (associated with a particular piece of hardware).

The /vol/rdsk and /vol/dsk directories are mirrors of one another. Any change
to one is reflected in the other immediately. The dev_t for a
volume will be the same for both the block and character device.

The default permissions for /vol are mode=0555, owner=root, group=sys. The default permissions
for /vol/dsk and /vol/rdsk are mode=01777, owner=root, group=sys.

Physical references to media or removable media devices (without media) are
obtained through /vol/dev. This hierarchy reflects the structure of the /dev name
space. The default permissions for all directories in the /vol/dev hierarchy are
mode=0555, owner=root, group=sys.

Partitions

Some media support the concept of a partition. If the label identifies
partitions on the media, the name of the media becomes a directory
with partitions under it. Only valid partitions are represented. Partitions cannot be
moved out of a directory.

For example, if disk volume 'foo' has three valid partitions, 0, 2,
and 5, then:

/vol/dsk/foo/s0
/vol/dsk/foo/s2
/vol/dsk/foo/s5

for block access and

/vol/rdsk/foo/s0
/vol/rdsk/foo/s2
/vol/rdsk/foo/s5

for character access.

If a volume is relabeled to reflect different partitions, the name space
changes to reflect the new partition layout.

A format program can check to see if there are others with
the volume open and not allow the format to occur if it
is. Volume Management, however, does not explicitly prevent the rewriting of a
label while others have the volume open. If a partition of a
volume is open, and the volume is relabeled to remove that partition, it
will appear exactly as if the volume were missing. A notify event
will be generated and the user may cancel the operation with volcancel(1), if
desired.